Growth speed

[Bismarck]

I'm a Norwood 2-3 receder (temple area). Still have nearly invisible unpigmented vellus hairs at the hairline and some "survivor" terminal hairs. Two weeks ago, I shaved the temples. Today, I noticed that the surviving terminal hairs are already visible again, but the vellus hairs not.
Is it possible that the vellus hairs are growing much slower than the terminal hairs? Or is it possible that a "vellus-shed" occured after 1 month of minoxidil-use?

Bismarck (experienced poster)